Hull for flying-boats.



.CURTISS 62 W. L. GILMORE.

HULL FOR FLYING BOAT APPLICATION FILED MAR. 13.1918.

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HULL FOR FLYING BOATS.

APPLICATION FILED MAR. 13. 1918.

11,294,414, Patented P131118, 1919.

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G. H. CURTISS & W. L- GILMORE.

HULL FOR FLYING BOATS.

APPLICATION FILED MAR. I3: 1918.

Patented Feb. 18, 1919.

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HULLFOR FLYING BOATS.

APPLICAl'lOh FILED MAR, 13. 1918 inivnmi Feb.

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GLENN H. CURTISS AND WILLIAM L. GILMORE, OF GARDEN CITY, NEW YORK, ASSIGN- 0R8 T0 QURTISS AEROPLANE AND MOTOR CORPORATION, A CORPORATION OF NEW YORK.

HULL FOB, FLYING-BOATS.

Specification of Letters Patent.

Application filed March 13, 1918. Serial No. 222,211.

To all whom it may concern:

Be it known that we, GLENN H. GURTISS and lVILLIAM L. GILMORE, citizens of the United States, residing at Garden City, in the county of Nassau and State of New York, have invented certain new and useful Improvements in Hulls for Flying-Boats, of which the following is a specification.

Our invention relates to flotation bodies which in many respects may be likened to both the hull of a flying boat and the pontoon of a hydro-aeroplane. It is characterized by an arrangement of interior frame parts which render it particularly adaptable to that type of flying boat in which the motor unit is inclosed within the boat body. The engine bed beams or su port-s extend longitudinally substantially t e full length of the hull and function conjointly as structural elements or stringers thereof. In this way the motor vibrational strains are eiiectually distributed as well as the enormous weight of the motor itself. The beam of the boat is widened to such an extent that it is extremely seaworthy even in the roughest seas. The bottom of the boat is constructed in hydroplane form and in cross section is somewhat more acutely V-shaped than heretofore,

Fin excrescences extend out laterally in direct continuation of the boat bottom throughout its full length. The fins however are not of a uniform width. They emanate from the extreme bow and widen out gradually to a point substantially amidships where they commence to decrease in width gradually so as to intersect at the stern. In this way the hull is strengthened longitudinally and its displacement per unit of length materially increased, Moreover, the hull is streamlined more effectually.

The bow of the boat is more or less a cross between the sc'ow and cut-water types. The bottom is longitudinally salient or convexed and provided with two rearwardly facing steps which are built-0n rather than built-in as heretofore. These two steps are located nearer the rear end ofthe hull than the forward end, the forward step lying substantially beneath the center of gravity. By providing two steps arranged in tandem suction and skin friction are minimized and t e craft e a led to come quickly to a hydropianing position. This permits of aerialflight without a. long preliminary run on the water.

Of the drawings Figure 1 is a top plan view of the flotation body showing more or less diagrammatically the shape of the hull and fins in plan.

Fig. 2 is a side elevation of the flotation body as illustrated in Fig. 1.

Fig. 3 is a front end elevation.

Fig. 4 is an enlarged longitudinal vertical sectional view showing the interior construction of the fore part of the hull.

Fig. 5 is a similar view showing the interior construction of the after part of the 'hull. (This figure is a continuation of Fig. 4.)

Fig. 6 is a transverse section on the line 6 6, Fig. 1, and

Fig. 7 is a transverse section on the line 77, Fig. 1.

In Fig. 1 it will be noted that the flotation body or hull is pointed both fore and aft and that its shape in plan is symmetrical or nearly symmetrical about a line intersecting it at an amidships point. In elevation the bow end is more or less blunt as is also the stern end although the generating lines which emanate from the stern end meet at the stem to improve the streamline at this point. Such construction gives us a relatively blunt entering portion and a gradually tapering tail portion which is best. The fore part of the hull is designated as an entirety by the numeral 10. It is provided with a bow cockpit 11 for an observer or passenger and an intermediate hatchway 12 for the motor unit (not shown). The center of gravity of the machine is designated C. G. in Fig. 1. That portion of the bull to the rear of the point C. G. will be hereinafter referred to as the after-body 13 as distinguished from the forebody 10. The afterboldy 13 is provided with a cockpit 14 for the pi 0t.

Lateral fins or excrescences 15 augment the hydroplaning area of the hull, strengthen it longitudinally, and materially increase its displacement. These fins 15 emanate from the extreme bow and terminate at the extreme stern, widening gradually as they approach an imaginary line' passing transversely through the hull at the point C. G. The fins also increase in depth from the bow end to a point substantially amidships so that the point of maximum displacement lies at or near the mentioned imaginary line. From this line the depth of the fins decreases gradually toward the stern although with less prominence.

The fins are preferably constructed as an integral part of the hull or body (although they may be made separately water tight) because of the added strength which is possible when thus made. The interior frame work can be extended out uninterruptedly from the keel line to the lateral margins of the fins. By giving the fins depth at their lateral margins the hull displacement is increased and the fins made stronger. This added depth is advantageous in that a sub-' stantially vertical surface is provided at the chines, whereby immersion of the fins, due to side winds, is prevented.

The bottom of the hull is characterized by convexity both longitudinally and transversely and is of acute V-form in transverse section throughout its full length. At the bow end of the hull the bottom is more acutely V-formed than at the rear end because of the advantage derived as a result of such construction. The bow end of the bottom thus partakes of both a scow and cut-wa ter form. Figs. 1, 2 and 3 illustrate these characteristics particularly well.

While hydroplaning, only the fore part of the bottom surface serves as a hydroplaning surface. The upward inclination of the after part of the bottom surface prevents its use in this capacity. The drag or resistance however which the after portion of the hull bot-tom would naturally ofi'er is minimized by the two step construct-ion. The forward step, designated 16, lies approximately beneath.the center of gravity and-the rear step 17, intermediate the step 16 and the stern. lVere the second step omitted there is apossibility that the skin friction and suction would be so great as to prevent breaking away from the water surface while hydroplaning. The hydroplaning surface of the hull is designated as an entirety by the numeral 18.

The interior frame-work of the hull includes a keel 19 which extends substantially the full length of the hull. At its forward end it extends upwardly on an easy curve to a point at the extreme bow end of the hull where it is reversely curved to extend back for a short distance so that it functions throughout such portion of its length as a deck stringer. Floors 20 extend out right and left from; the keel 19 to provide a foundation for the bottom planking 21. These fioors are substantially uniformly spaced and are fastened at their extremities to chine stringers 22 co-extensive with the bottom outside marginal edges of the fins. Tntermediately the floors 20 are supported by engine bed beams 23 of a' construction such that they not only function as motor supports but also as intimate structural elements of the hull. These engine bed beams 23 extend substantially the full length of the hull and comprise vertically separated beam sections 2% and 25 having post connections 26. The upper beam section 24 is 7 substantially straight throughout its full length while the lower beam section 25 is bowed so that at or near its ends it intersects the upper beam section 24. Fittings 27 are provided at stations along the beams 21 and to receive the ends of the posts 26 and at the same time provide anchorages for wires 28 cross arranged between the beam sections to effectually brace them (see Figs. t and 5). The'fioors 20 are notched to receiie the lower beam sections 25 of the motor supports (see Fig. 6). This not only strengthens the floors but gives the supports themselves a good solid foundation. This arrangement and construction of the motor supports is such that the vibrational strains of the motor which is mounted directly upon them are distributed uniformly throughout the full length of the hull. Landing and hydroplaning strains are also effectually distrib uted as a result of this arrangement.

Fin. frames 29 are provided at the outer marginal edges of the fins. These frames interconnect the chine stringers 22 and 3. 0 stringers 30 located at the top outside marginal edges of the fins. It will be noted that these frames 29 are of a size approximately equal" to the floors 20 that added strength at the fin edges may be provided. Frames 31 together with stringers 32, seam battens 33 and bearers 34 constitute the remaining elements of the interior hull frame-work. The bearers 3% like the engine bed beams 23 serve a two fold purpose. They not only afford a foundation for the floors 20 but they support the weight of the wing structure which is mounted directly upon them. Each bearer comprises a beam section 35, a beam section 36, vertically extending posts 37 and diagonal braces 38. The braces extend forwardly and downwardly from the upper beam section 35 and like the posts 37 interconnect the beam sections in such a manner that the sections constitute in effect a vertically latticed beam. Appropriate fittings 39 are provided at the extremities of the posts 37.

The lower beam sections 36 of the bearers 34 are curved longitudinally and extend for the greater portion of the length of the hull. They are connected at their for- Ward extremities to the keel at its extreme forward end. The upper beam sections 3-5 are not so extended. While they are com nected with the keel 19 at its extreme rearward end they terminate forwardly at a point somewhat in advance of the imaginary line intersecting the point C. G. Throughout their length they are rearwardly and downwardly inclined from their forward end to function not only as wing structure supports but also as rails upon which the wing structure slides back when shed as a unit with the false decking provided at the after end of the hull. The sheddable feature of the craft is described at length in a co-pending application Serial No. 222,212, filed concurrently herewith.

Although the wing structure forms no part of the hull per 86 it will be noted that the beams of the wing rest directly upon the rails or upper beams of the bearers and that these beams, if released, are free to slide back until shed clear of the hull since the rails are free from obstruction throughout.

nediateiy and at various points out its length the hull is divided by a number of water tight of varying heights according The bulkheads not only transce the hull but by reason of their ion l terally to the fin edges they y brace the tins. Moreover, they act as si eners for the engine bed supports and for the hearers. The break provided in ii bottom near its stern end (see Fig. u. :1 water prepeller and water rudder I It is intended that the water aid propeller be withdrawn into an 1 oropri i s housing when the craft is used As this does not however ar description will be foregone.

"ich is emphasized is be wing structure and The rectiotns of the bearers 34 are stiff wires to the lowere motor supports at points di- 1 each wing beam. in this way of the wing structure are carhe hull and distributed over fail length. Furthermore notor itself acts directly so that the hull in its .ed a correlated whole.

stening devices or fitcams are held in is suiii cient to say ittin "s, a" specifi dih the a. rd

n: describ oi the that. no Lillllt imposed by the claims are intended to be made.

What is claimed is:

1. A hu-ll for flying boats having lateral fin excrescences of gradually increasing width from the opposite ends of the hull, the length of the excrescences being such that they extend substantially throughout the full length of the hull and at their extremities merge into the hull without a substantial break in its continuity.

2. A hull for flying boats having fin excrescences of gradually increasing depth at their outer margins from the bow end of the hull to a point substantially amidships. from which point the fins at said outer margins gradually decrease in depth as they continue toward the stern.

3. A hull for flying boats having lateral fin excrescen'ces of gradually increasing depth at their outer margin from the bow end of the hull, the depth of the fins at the amidships portion of the hull being greater than the depth rearwardly of said point, the decrease in depth being gradual from'said amidships portion aft.

4. A hull for flying boats including longitudinal stringers having lon itudinal salient bottom edges and straig t top edges, the arrangement of the stringers being such that the bottom edges thereof directly contact the framework of the hull bottom while the top edges directly support the power plant for the-boat.

5. A hull for flying boats including floors which provide a foundation for the hull bot tom, together with longitudinal stringers of a construction such that they directly contact a plural number of the floors, said stringers transversely of the hull being spaced apart a distance equal to the space between the supporting elements of the power plant whereby the latter may rest directly upon said stringers.

6. A hull for flying boats including stringers as structural elements of the boat framework, the depth of the stringers ing such that they not only streng lhull longitudinally throughout a su; oortion of its length oy contact with ottom framework th eof, but conjoiittly function as supports tor the power planh said stringers being transversely spaced distance equal to the space b een the sup-- porting eien'zent oi' the e-wet ant.

7. A huli i b including stringers as strut framework,

s r ions being l; s of the hull """uos" direct contact wit torn and connected "as, t e constr u 8. A hull for flying boats including bearers of a construction such that they extend longitudinally of the hull throughout the greater portion of its length, the bottom edges of the bearers being-in direct contact with the floors of the hull bottom and the top edges in direct contact with elements of the wing structure.

9. A hull for flying boats including bearers as structural elements of the hull framework, each bearer comprising a plural number of sections arranged one abOVe the other, the placement of the lowermost sections being such that they are in direct contact with the floors of the hull bottom, the placement of the uppermost sections being such that they afford a support for the wing structure of the craft, said sections being-directly interconnected by diagonally extending braces and vertically extending posts.

10. A hull for flying boats including bearers as structural elements of the hull framework, each bearer comprising a plural number of sections arranged one above the other, the bottom edges of the lowermost sections being in direct contact with the floors of the hull bottom, the top edges of the uppermost mean-e sections being in direct contact with the structural elements of the wing structure, said uppermost sections being rearwardly and downwardly inclined from their forward ends, the bearers themse ves being arranged respectively in the approximate vertical plane of the opposite sides of the hull.

11. A hull for flying boats including bearers and longitudinal stringers as structural elements of the hull framework, the bottom edges of the bearers being in direct contact with the framework of the hull bottom and the top edges in direct contact with structural elements of the airplane Wings, and the bottom edges of the longitudinal stringers likewise in direct contact with the bottom framework, the top edges of said stringers affording supports for the power plant, the stringers being spaced apart a distance equal to the space between the supporting elements of the power plant and the bearers spaced apart a distance equal to the, Width of the hull.

In testimony whereof we hereunto afiix our signatures.

GLENN H. CURTISS. NlLLiAl /l L. GILMORE. 

